Time operated and/or remote controloperated electro-mechanical lock



E- O'BRIEN 3,340,710

OPERATED Sept. 12, 1967 TIME OPERATED AND/OR REMOTE CONTROL 7ELECTRO-MECHANICAL LOCK Filed Feb. 14, 1966 3 Sheets-Sheet 1 ---EToLoich BOW INVENTOR. EUGENE 0' BRIEN ATTORNEYS E. O'BRIEN 3,340,710

OPEHATED Sept. 12, 1967 TIME OPERATED AND/OR REMOTE CONTROLELECTRO-MEGHANICAL LOCK 5 heets-Sheet 8 Filed Feb. 14, 1966 Tmw HOAC.

INVENTOR. EUGENE O'BRIEN ATORNEYS Sept. 12, 1967 TIME OPERATED AND/ORREMOTE CONTROLOPEHATED Filed Feb, 14, 1966 E. Q'BRIEN ELECTRO-MECHANICALLOCK 3 Sheets-Sheet 5 I INVENTOR EUGENE O'BRIEN ATORNEYS United StatesPatent 3,340,710 TIME OPERATED AND/0R REMOTE CONTROL- OPERATEDELECTRO-MECHANICAL LOCK Eugene OBrien, Philadelphia, Pa., assignor toCommand-Lock, Inc., a corporation of Pennsylvania Filed Feb. 14, 1966,Ser. No. 527,312 The portion of the term of the patent subsequent toFeb. 14, 1983, has been disclaimed Claims. (Cl. 70-271) This is acontinuation-in-part of my copending patent application Ser. No.324,012, filed Nov. 15, 1963, now US. Patent 3,234,766.

This invention relates to a time controlled lock, the primary object ofwhich is toprovide a construction in which the lock is automaticallyclosed at a pre-set time and automatically re-opened after a pre-setinterval thereafter, the lock being key or manually operable only byauthorized personnel in said interim. It also relates to a remotecontrol-operated lock in which the opening and closing thereof isautomatically effected by a means other than a timer, such as by manual,pressure or temperature operation. A general object of this invention isto provide a new and improved electrically operated lock.

Another object of the invention is to provide a time controlled lock ofthe character described in which the latch bolt of the lock is extendedinto the closed or retracted into the open position by a timer actuatedmotor in such a manner that the motor shuts 01f at the end of a movementcorresponding to the travel of the latch bolt thereby utilizingelectrical energy only for the short time corresponding to that requiredto extend or retract the bolt.

Another object of the invention is to provide a time controlled lock ofthe character described in which the timer actuated motor is operativelyconnected to the latch bolt by a means which permits the retractioncycle to complete itself and which cuts off the motor even though thelatch bolt may be temporarily restrained from movement, as by jamming inthe keeper, said means storing the retraction energy and acting to movethe bolt to the retracted position when the restraining force in thekeeper is eventually released.

Another object of the invention is to provide a time controlledelectromechanical lock which does not necessarily rely upon batteries asa source of current and which employs instead circuits of oppositepolarity and switches therein in which are operatively connected anelectrical source, a reversible motor and the lock bolt in such a mannerthat at the end of each stroke of the latch bolt a switch is actuated tobreak one of the circuits and cut olf the motor but move to such aposition that when the timer re-activates the motor at the pre-set timethe opposite circuit is automatically closed.

Another object of the invention is to provide a timer actuatedelectromechanical lock which can be opened mechanically from the insideand by key operation from the outside only by authorized personnelduring the interval when the lock has been pre-set to remain closed.

Another object of the invention is to provide an electromechanical lockwhich can be actuated by a remote control push button. Another object isto provide a timer actuated electromechanical lock which can be openedwith a mechanical key only during the intervals when the lock has beenpre-set to be so opened.

These and other objects of the invention will become more apparent asthe following description proceeds in conjunction with the accompanyingdrawings, wherein:

- FIG. 1 is a perspective view of the lock shown installed;

FIG. 2 is a side elevational view of the instant lock,

3,340,710 Patented Sept. 12, 1967 the cover having been removed todisclose the working parts;

FIG. 3 is an exploded perspective view of the latch bolt and slideactuating bar therefor;

FIG. 4 is a diagrammatic view of the timer, motor, latch bolt actuatorand circuit therefor;

FIG. 5 is a schematic side elevational view of a modified form of thisinvention; and

FIG. 6 is a schematic side elevational view of another modified form ofthis invention.

Specific reference is now made to the drawings in which similarreference characters are used for corresponding elements throughout.

The lock is generally indicated at 10 and comprises a housing 12,preferably rectangular, and a cover 14 therefor which encloses the lockmechanism. The rear plate 16 of the housing is itself secured as byscrews 18 to a door 20 in any desired position so that one of its sidewalls 22 is adjacent the vertical edge of the door and proximate to asuitable keeper 24 which has been mounted on the door jamb 26.

The lock mechanism is itself secured upon a substantially rectangularmounting plate 28 which is smaller than the opening 30 closed by thecover 14 so that the mounting plate can be readily slipped into thehousing and there secured. Thus, where the door structure makes itdiflicult to install the entire lock as a unit, by the presentarrangement, first the housing 12 can be readily secured and then themounting plate. Mounted on and extending perpendicular to the rearhousing plate 16 and through a hole in the door is a continuous wafertype lock 32 having a rotatable plug 34 which is operable by a key 36that is removable in two positions apart. The plug extends into thehousing and through a cut-out 38 in the mounting plate 28 and secures acam 40 on its inner end.

The mounting plate 28 has an upstanding wall 42 with a central opening44 through which extends a conventional tubular-type spring latch. Thelatch includes a tube 46 secured to a plate 48, the latch bolt 50 beingslidable in the tube and normally urged by a spring 52 in the tubetowards the extended or closed position through a hole provided in theplate 48 and an opening in the side wall 22 of the housing thence intothe keeper. The wall 42 of the mounting plate 28 is secured by screws 54to the latch plate 48 and then further recessed screws 56 are made toextend through the side wall 22 of the housing, the plate 48, and thewall 42. Additional screws 58 are used to fix the mounting plate 28 inits final position in the housing.

The inner end of the latch bolt 50 includes a flattened reduced shank 60and a laterally enlarged head 62. A latch bolt actuator 64 is providedwhich extends vertically across the mounting plate 28 and consists of amember which is substantially U-shaped in cross-section having a pair ofspaced plates 66 and 68 connected by a web 70, the plate 68 having alaterally extending enlarged portion 72 provided with an open-endedslot-74 for receiving the shank 60 and head 62 of the latch bolt 50 andetfect coupling of the actuator 64 to the bolt. The plates 66 and 68 arespaced apart a distance greater than the total movement of the latchbolt 50. The mounting plate 28 secures a pair of upstanding spaced bars76 through which extend, slidably, rods 78 secured to the actuator 64 toguide the latter in its slidand by a threaded member 82 which engagesthe mounting plate 28 and rear housing plate 16, the latter be-' inglocked in place by a key 84. To one side thereof a shaft 86 is rotatablymounted on the cover and extends into the housing, the inner end thereofsecuring a cam 88 and the outer end'an operating handle 90.

A spring 92 connects the cam with the cover and urges it away from theactuator. Thus, it will be seen that rotation of the handle 90 in acounter-clockwise direction will cause the cam 88 to engage the actuator64 and retract the latch bolt. Similarly, key operation of the barrel 34will cause the cam 40 to engage the actuator 64 and retract the latchbolt.

Mounted on the plate 28 is a reversible DC motor 94 whose shaft drivesgearing 96, see FIG. 4, one of which is a sector gear 98 having anupstanding arm 100 which extends through the motor casing, as seen inFIG. 2. Such a motor and associated gearing is commercially available asa Duramite-Multi Servo unit supplied by Bonner Specialties of LosAngeles, Calif. A spring 102 is terminally hooked as at 104 to the arm100 and behind the plate 66 as at 106 through which it is freelyslidable. The spring rating of spring 102 is such that it is strongerthan the latch spring 52 but weaker than the motor and gears for apurpose later to appear.

A conventional timer 108 is provided in the form of an electricallyoperated clock having trippers on its clock face which can be set atdesired time intervals to open and close the instant lock, the trippersactuating a single pull, double throw toggle switch 110. Such a timer isavailable from Tork Time Controls, Inc., of Mt. Vernon, N.Y., as TorkTime Switch, Model 7120. The switch 110 is interposed in two circuits ofopposing polarity, 112 and 114, each including the motor 94 and a shuntswitch 116 energized at the end of each stroke of the sector gear 98 tobreak the circuit to the motor and prepare the opposing circuit forclosure by mere actuation of the toggle switch 110 at the next timeinterval.

In use, suppose one wished to arrange for the lock to automaticallyclose at pm. and automatically reopen at 9 am. the next morning. One ofthe trippers of the timer 108 is set at 5 pm. and the other at 9 am. andthe clock is set at the correct actual time. When the first tripperarrives at 5 pm. it throws the pole of the toggle switch 110 to theposition to engage the terminal 118 and close the circuit 112 drivingthe motor in one direction and through the gearing 96, 98 the arm 100from left to right on FIG. 2 or from a remote to a close position withreference to the keeper. In so doing, the tension on spring 102 isreleased allowing the compression latch bolt spring 52 to take over andurge the latch into the extended or closed position, the latch pullingthe actuator 64 along. At the end of its travel, the sector arm 100actuates the shunt switch 116 to break the circuit 112 by causing itspole to move away from terminal 120 which it had previously contacted,thus cutting off the current to the motor. At the same time, the pole ofswitch 116 moves to engage the terminal 122 of the shunt switch whichwould normally close the circuit of opposite polarity 114 but for thefact that the pole of the toggle switch 110 has not yet engaged thesecond terminal 124. When the second tripper arrives at 9 a.m., itactuates the pole of the toggle switch 110 to engage the terminal 124thereby automatically completing the circuit to the motor and reversingits rotation. In so doing, the sector arm 100 moves away from the keeperor from right to left of FIG. 2 extending the spring 102 somewhat whichin turn pulls the actuator 64 to the left or away from the keeper andretracts the latch bolt 50 against action of its compression spring 52.At the same time, the pole of shunt switch 116 moves olf terminal 122and engages terminal 120 to prepare the other circuit 112 to be closedonly by the action of the timer tripper when it arrives at the nextpre-set interval.

In the event that the latch bolt is jammed in the keeper for somereason, the arm 100 will complete its stroke to the left and shut offthe motor while the spring 102 is fully extended. The spring thereforeacts to store the retraction energy and whenthe jamming is mechanicallyreleased, the spring 102 will itself retract the actuator 4 64 and latchbolt 50, thus preventing overload on the motor.

In the further event that an authorized person inside the enclosurewants to release the lock from the inside, a solenoid 126 may beprovided in the housing whose core 128 is operatively connected by awire 130 to the plate 66 behind which it is hooked as at 131 and throughwhich it is freely slidable, there being a push-button switch 132 at anydesired location to close the circuit to the solenoid and therebyretract the actuator 64 and latch bolt 50. If desired, the solenoid canbe located outside of the housing and operatively connected to theactuator 64 by other means.

When the bolt 50 is in its extended position and engages the keeper, theactuator 64 is at its furthest position towards the keeper or to theleft of FIG. 2. If the timer has acted to cause the latch bolt to lockand has not yet arrived at the time to open it, those in the enclosurecan let themselves out by rotating the handle so that cam 88 abuts theplate 68 of actuator 64 to retract it and the latch bolt. From theoutside this can be effected only by an authorized person having key 36which when used to rotate barrel 34 in one direction will cause its cam40 to abut the plate 68 of actuator 64 to retract it and the latch bolt50. The conduit 134 from the timer 108 enters the housing through agrommeted opening in the side Wall 136 of the housing opposite wall 22.Also, because the solenoid wire and retractor spring 102 are freelyslidable through plate 66, the latch bolt can be manually retractedwithout any resistance from either the wire or spring and the latch boltcan be retracted by the solenoid without any resistance from theretractor spring 102.

It should be understood that the switch 110 can be operated by manual,pressure or temperature means, instead of a timer, in which case themechanism becomes a remote-control-operated electro-mechanical lock. Forthe purposes of manual remote operation, it has been found desirable toprovide a set of indicator lamps for the operator and associatedswitches at the lock. For example, a switch has been provided in keeper24, which is efiective to energize a lamp when the bolt 50 is retracted;another switch has been provided within housing 12 to be operated byactuator 64 in its different positions so that a lamp is lit or notdepending on the operated condition of the actuator. Thereby, theoperator is able to monitor the condition of the lock at all times.

As shown in FIG. 4, a key-operated switch unit in lock housing 12provides a secondary control of the motor 94. The unit 150 includes asingle-pole, normallyopen switch 152 that is connected in series in thelockopening circuit 114; for example, it may be connected as shownbetween the motor 94 and switch 116. The unit 150 also includes asuitable operator for the switch 152, one form of which is a mechanicallock and key 154, which serves to mechanically actuate switch 152 wheninserted therein. The unit 150 may take the form of any suitablekey-operated switch; for example, the cam 40 actuated by key 36 may beused to operate a simple single pole switch when it is rotated aquarter-turn. Such a key operator unit may be installed at any desiredlocation within the housing 12 where it does not interfere with themechanism, or such a key operated unit may be installed at a separatelocation on the door or door jamb and appropriate wiring connectionsmade to form an appropriate control circuit such as the circuitillustrated in FIG. 4.

With the switch unit 150, the operation of the lock under the control ofthe timer 108 is similar to that described above during the closingoperation via circuit 112, which is effective to extend the bolt 50 intokeeper 24. However, when the timer operates the switch 110 to theposition illustrated in FIG. 4 to initiate retraction of the bolt 50,the circuit 114 is not completed to energize the motor 94 until a key154 is inserted in unit 150 to close the switch 152. When the switch 152is closed, the motor is energized and the bolt 50 is retracted in themanner described above. Thereby, a double security control of the lockis provided, and personnel may be supplied With copies of the key 154that are only ef ective to open the lock during the time intervals foropening established by the timer 108. The switch 152 does not preventproper closing operation by the timer 108 to extend the bolt 50; andonce so extended, the key 154 is inefiective to energize the motor 94and open the lock until timer 108 throws switch 110 to the boltretraction position shown in FIG. 4.

In FIG. 2, spring 160 is connected between a pin 162 fixed to mountingplate 28 and the arm 100 of motor 94, and acts in a direction to assistthe motor 94, acting via arm 100, in extending spring 102 or compressingbolt spring 52. The balance spring 160 is extended by the arm 100 whenmotor 94 is operated for actuation of the bolt 50 to its extendedposition. The extension of spring 160 stores much of the energy of themotor during that portion of the operation. Upon operation of motor 94to retract the bolt 50, spring 160 assists arm 100 in the retractionoperation, and the energy stored in the spring 160 is transferred tocoupling spring 102 or to the "bolt spring 52, one of which is extendedduring this bolt retraction operation depending on whether the bolt 50is struck in the keeper 24, or whether it is readily retracted. Thebalance spring 160 has less spring force than the coupling spring 102and serves to balance the load on the motor 94 to require approximatelyequal drive of the motor in both the bolt-extension and bolt retractionoperations.

Without the balance spring 160, the bolt spring 52, compressed by theretracted bolt 50, stores the motor energy and assists the motor in thebolt-extension operation; while the spring is a load during boltretraction. Since the motor operation, without the balance spring 160,is not the same for bolt retraction as bolt extension, one can provide asmaller energizing current during the boltextension operation tocompensate for the unbalance and provide smoother operation. However, ithas been found that the balance spring 160 serves not only to balancethe load on the motor for the most part, but also during normaloperation, the spring 160 tends to reduce substantially the load onmotor 94. The reduction in load results from the transfer of energy fromthe balance spring to the bolt spring 52 during bolt retraction, andback from the bolt spring to the balance spring during bolt extension.When the bolt 50 sticks in the keeper 24, energy i transferred from thebalance spring 160 to the coupling spring 102, and after the bolt isreleased from the keeper 24, from the coupling spring 102 to the boltspring 52 to retract the bolt. When motor 94 is operated for boltextension and the bolt 50 is blocked from entering the keeper 24, themotor 94 has the additional load of extending balancing spring 160 sinceit is not assisted by bolt spring 52 at that time. However, this is aninfrequent occurrence, relatively speaking, so that the overall loadingof the motor 94 is substantially reduced by use of the balance spring160.

A modified form of the invention is illustrated in FIG. 5, in whichparts corresponding to those described above are referenced by similarnumerals with the addition of a prime A bolt 50' is biased outwardly inthe extension direction for engagement in a keeper (not shown) by a pairof compression springs 52. Each of these springs 52 lies between andbear against a shoulder on the 'bolt 50 and a guide post 164, which postis fixed to the lock mounting plate 28' and slidably receives a guiderod 166 that is secured to the bolt 50 and passes through spring 52. Apull rod or arm 100" is slidable between guides 168 and within a chamberformed within a yoke extension 170 of the bolt 50. A compressioncoupling spring 102' bears between an inner shoulder of the yoke 170 anda shoulder 172 at the end of pull rod 100" and tends to bias the bolt 50in the retraction direction. At the end of pull rod 100", a slottedcrosshead 174 receives a pin 176 eccentrically located on a rotatabledisk 178, the center of which is rotatable by way of a shaft coupling toa motor 94', which includes an appropriate gear box 179. The motor 94'may be reversible motor or it may be a unidirectional motor that can bealternating current -or direct current energized. A balance spring 160',shown as an extension spring, is connected between a fixed post 162 andthe cross-head 174 and biases the pull rod in the bolt-retractiondirection. The crosshead 174 operates a toggle-switch 116 when it ismoved to either of its extreme positions by way of two operator arms 182and 184 connected to the pole of switch 116, which are respectivelyengaged by the crosshead 174 at opposite ends of its path.

In operation, the bolt 50 is biased by springs 52 to its extendedposition for engagement in the keeper in the position illustrated inFIG. 5. Where motor 94' is a reversible direct current motor, thecircuit FIG. 4 may be used in the manner described above, in whichbatteries (or any other equivalent power supply) of opposite polan'ty(as shown in FIG. 4) may be used to energize the opening and closingcircuits 114 and 112, respectively, and switch 116' is used in place ofswitch 116 in FIG. 4. Where an A-C motor is used, it is operated in asingle direction, and the direct-current power supply, shown asbatteries in FIG. 4, may be replaced by an A-C line with the pair of A-Cpower terminals being connected in reverse fashion to the two circuitsections 112 and 114, or coupled thereto by a transformer with separatesecondary windings for the two sections 112 and 114. In thatarrangement, the motor 94' is energized via circuit 114 to retract thebolt 50, and via circuit 112 to extend the bolt 50'. That is, whenenergized by a circuit 114, motor 94' rotates disk 178 a half-cycle, atwhich pin 176 is in the phantom position 176', to move crosshead 174 andpull rod 100" to the left, compress coupling spring 102, and pull bolt50' to the retracted position against the bias action of springs 52'.The chamber of yoke 170 is somewhat longer than the required boltretraction to permit adequate compression of spring 102' and relativemovement if bolt 52' is stuck in its keeper. When the crosshead 174reaches its extreme bolt-retraction position, switch arm 184 is operatedto actuate switch 116' to the opposite position. Thereafter, when switchis moved to complete the boltextension circuit 112, the motor 94' isagain energized to continue the rotation of disk 178 another half-cycle,moving pull rod 100", which relieves. the compression of spring 102' andpermits bolt 50' to be extended by bias springs 52'. When crosshead 174completes its movement to a position illustrated in full lines in FIG.5, switch arm 182 is actuated to operate switch 116 to the oppositeposition, and the circuit is in condition to start the next cycle ofbolt-retraction and extension.

The balance spring operates in a fashion similar to the balance spring160 described above; it tends to balance the load on motor 94 during thetwo half-cycles of operation for bolt retraction .and extension,respectively, and it reduces the load on the motor during normaloperation.

In FIG. 6 another modified form of the invention is illustrated; partscorresponding to those previously de scribed are referenced by similarnumerals with the addition of a double-prime Mounted on a side wall 22"of the lock housing is a conventional tubular type spring latch (similarto that shown in FIG. 1); the latch includes a tube 46" secured to themounting plate 48', a latch bolt 50" that is slidable through the plate48" and Within the tube 46" and that is normally biased by a spring 52"towards the extended or locked position into the keeper commonlyassociated with such a bolt. The spring 52" bears between a shoulder onthe bolt and the opposite inner wall of the tube 46". At its inner end,latch bolt 50" includes a rectangular shank 60" and head 62". A latchbolt actuator 64" is formed as a fiat member fixed to mounting plate 28"and having upstanding walls 200 and 202 at each end thereof as well asan upstanding guide member or intermediate wall 204. The bolt shank 60"is slidably received within a rectangular slot in the wall 200, and itshead 62" is retained thereby. The walls 202 and 204 have bearingopenings that slidably and rotatably support the shaft ends of anendless-worm adjustment screw 206. The endless-worm 206 has anintermediate portion that is formed with transverse left-hand andright-hand helical grooves that operate a follower arm 100 in the formof a rectangular member bearing against the flat plate of actuator 64"so as to be nonrotatable. Arm 100" has therein a rotatable member 210with a groove-following blade 212 formed at the bottom thereof whichengages in the helical grooves of endless worm 206. This mechanism is awell known device for providing reciprocating movement of the followerarm 100 back and forth along the worm as the worm shaft 206 rotates inbut a single directioneln a commonly formed construction of thismechanism, the grooves at their ends are arranged to rotate the followerblade 210 a partial turn; thus, as it reaches the end of the helicalgroove in one direction it engages the helical groove in the otherdirection and thereby reverses the direction of translation of theentire follower member 208.

Bearing between follower arm 100" and wall 202 is a compression spring102, which serves as a coupling between the arm 100" and bolt actuator64". That is, as follower arm 100 is moved to the right (as viewed inFIG. 6), coupling spring 102' tends to be compressed and to move boltactuator 64 to the right to retract the bolt 50"; as follower arm 100"is moved to the left, coupling spring 102" tends to be relieved topermit bolt actuator 64 and bolt 50" to be moved to the left under theaction of bolt spring 52".

An extension arm 212 secured to follower arm 100", reciprocatestherewith, and is biased to the right by extension spring 160" connectedbetween arm 212 and a fixed post 162". Spring 160" serves to opposesomewhat the bias of bolt spring 52' and to balance the load on motor224. Extension arm 212 is also used to actuate a toggle switch 116", asthe follower 100" is moved to its extreme positions, by engagement witharms 182 and 184" attached to the switch 116" in a manner similar tothat described above. An extension 214 of a rear wall 202 is engaged bya cam 40", which is secured to the rotatable plug 34" of a continuouswafer lock in a manner similar to that described above with respect toFIG. 1; thereby, a mechanical key can be used to operate the lock androtate the cam 40" against the extension wall 214 and move the boltactuator 64" to the right for bolt retraction.

The endless worm shaft 206 is guided in the walls 204 and 202 and ismounted in a fixed thrust bearing 216 and secured from reciprocation byappropirate shaft collars on either side of the thrust bearing. Theshaft is connected via a universal coupling 218 to the output shaft 220of a gear train 222 and motor 224. The motor 224 may be any suitableform of single-direction motor, such as an AC motor. The universal 218assures appropriate parallel alignment of the worm shaft 206 and driveshaft 220.

In the position illustrated in FIG. 6, the bolt 50" is in the extendedposition for interlocking with a keeper. It is biased to this positionby bolt spring 52", the balance spring 160" is extended, being weakerthan the bolt spring 52", and the coupling spring 102 is in its normal,substantially uncompressed condition. When motor 224 is energized byoperation of switch 110 (using the circuit of FIG. 4 with a suitable A-Cor power supply), shaft 206 is rotated in the direction of the arrow todrive the endless worm portion thereof as a right-hand screw, whichmoves the follower arm 100" to the right (assisted by balance spring160") to compress coupling spring 102 so as to overcome the bias ofspring 52" and retract the bolt 50". When the bolt 50" is fullyretracted, the follower arm 100 reaches the end of the right-handhelical groove of the worm 206, and the extension arm 212 operates thetoggle switch to de-energize the motor 224, which stops substantiallyinstantaneously due to the load thereon; the groove follower blade 210is rotated and aligned with the left-hand groove to be ready to start onthe return path upon re-energization of the motor 224. Upon operation ofswitch in the opposite direction, motor 224 is energized again androtates endles worm shaft 206 in the same direction to drive thefollower arm 100" along the left-hand groove back to the positionillustrated in FIG. 6 to operate the switch 116" and stop the motor 224.The movement of follower arm 100" to the left, is transmitted bycoupling spring 102" and bolt actuator 64" to permit bolt extensionunder the action of bias spring 52"; at the same time balance spring isextended to the condition illustrated.

In the embodiment of FIG. 6, a DC motor with the opposite polarities ofpower supply shown in FIG. 4 may be utilized; in which case, the endlessworm 206 may be replaced by a conventional worm gear or adjustment screwengaging in a threaded follower arm of conventional form, and oppositerotations of such a worm gear produces the desired reciprocation of thefollower arm in forward and reverse directions. Thus, in each of theabove-described embodiments of the invention, a reversibleelectromechanical motor device is provided in which a motor arm iscoupled by means of a spring to an actuator for a springbiased bolt, andreversible operation of the motor arm in opposite directions producesthe desired retraction and extension of the bolt. This invention is notlimited to any particular type reversible or reciprocating motor device;forex ample, a solenoid or an electrical linear actuator with anappropriate mechanical drive may be used as the electric motor whichprovides reversible, reciprocating movement of a motor arm (such as thearm 100, 100" or 100") for bolt retraction and extension, the motor andmechanical drive being such as to maintain the motor arm in its extremepositions when the motor is not energized. With an appropriatemechanical drive, motor and size and .weight of the various parts, it isnot necessary to provide for braking of the motor or indexing of themotor arm in its extreme positions of travel. However, if necessary dueto particular requirements (such as for large or extra heavyconstruction), dynamic braking of the motor or a similar expedient maybe employed.

For greater security, a tubular dead latch mechanism may be used inplace of that of spring bolt 50"; such a dead latch mechanism operatesas a spring bolt in the manner described, but, once engaged in itskeeper, the dead latch cannot be retracted by forces applied to theouter end of the bolt. The free movement needed for the bolt of such adead latch is provided by the relative sliding movement permittedbetween the bolt shank 60 (60") and bolt actuator 64 (64"). Moreover,this invention may be used for electrical control of the operation of areleasable keeper instead of the bolt of a lock, and such a keeper maybe extended into engagement with the bolt and retracted out ofengagement in a manner similar to that described above.

Thus, in each form of this invention, no standby power is required tomaintain the lock in either a locked or an unlocked condition; that is,with the bolt extended or retracted. The mechanism (e.g., worm andpinion or scotch yoke) coupling the electric motor to the motor arm 100,100' or 100" has a mechanical advantage going from the motor to themotor arm and, therefore, is of such a nature as to 'be moved only bymotor power and to remain unaffected by forces applied from the bolt endof the mechanism (e.g., by the energized coupling spring when the boltis not free for retraction). Where binding of the bolt in the keeperoccurs (due to common faults such as sagging of the door hinges orWarping or bad fit of the door), the electric motor is not overloaded inattempting to retract the bolt; instead, the motor operates only for thetime necessary to store in the coupling spring the energy required forbolt retraction. This energy continues to be stored until the bolt isfreed, since the motor arm is retained in position by its drivemechanism. When the door is subsequently manipulated, the bolt isultimately freed, and the coupling spring retracts it to completeunlocking of the door. Similarly, the motor action in the reversedirection (where the bolt is blocked from extension into the keeper) isfor the short time needed to transfer the energy for bolt extension andto make it available in the bolt spring, where it is stored until thedoor is manipulated to permit extension of the bolt. Thus, in neithercase is there any danger of overloading the motor such as may damage Theenergization of the motor is for but a short period of timecorresponding to that required to actuate the coupling spring 102, 102'or 102 and to store the energy therein for bolt retraction, orcorresponding to that required to actuate the balance spring for boltextension. In the above described embodiments, the switch 116, 1.16 or116" detects the appropriate movements of the motor arms 102, 102' or102 and cuts off the motor when the required motor arm movement iscompleted. Thereby, an accurate determination is made of when to cut offthe motor. The switch 116 may take the various forms noted above andequivalent forms such as commutator brushes and the like. Alternatively,the switch 116 may be operated indirectly; for example, the switch 110may also be connected to known timing circuits or other known timingdevices; and the operation of switch 110 to energize the motor viacircuit 112 or 1.14 may also be effective tooperate an associated timingcircuit or device that actuates switch 116 to the opposite positionafter a certain time period that is suflicient for the motor to move themotor arm to the proper extreme positions.

Each form of the invention provides a slip-joint or movable connectionbetween the motor arm and the bolt actuator, by way of, for example, theconnection of the coupling spring; thereby, together with an appropriatemechanical lock and operator for the bolt actuator, mechanical overrideof the electrical control is provided for bolt retraction. Moreover, adouble-security control of the bolt is made available by means of amanually-operated switch 152 that must be closed in addition tooperation of switch 110 to energize the motor and retract the bolt.Thus, this switch 152 is effective only during conditions or timeperiods established by the operation of switch 110. This switch 152 maybe any desirable :form of key-operated device or it may be actuated by acombination push-button switching device. The security requirements forthe operation of switch 152 may be of a lesser character since it isonly effective during limited times.

The invention is not limited to any particular form of electric motor;rotary or linear motors may be used, either A.-C. or D.-C. In the caseof rotary motors, the reversing action of the motor arm or bolt actuatorcan be supplied by reverse rotation of the motor itself or itsassociated mechanical drive.

By means of a balance spring 160, 160' or 160", the motor loading issubstantially the same when operating in either the bolt-retraction orextension portion of the cycle. In addition, this spring serves toreduce the peak loading on the motor during normal operation; thisreduction of loading comes about as a consequence of storing energy inthe balance spring during the bolt-extension half-cycle (when both thecoupling spring and bolt spring are aiding the motor drive), and usingthe stored energy for bolt retraction (when both the coupling and boltsprings are opposing the motor drive). The energy stored in the balancespring may come entirely from the motor during the boltcxtensionhalf-cycle, or it may come at least in part from the bolt and couplingsprings as they return excess energy to the system. It is preferred thatthe balance spring serve to balance approximately the load on the motorfor each of the different half-cycles during normal operation; however,this relationship may vary with the lock desi n, and the balance springmay be chosen to provide a somewhat greater (or lesser) load on themotor during the bolttion and arrangement of parts may be made withoutdeparting from the spirit of the invention and the scope of the appendedclaims.

What is claimed is:

1. An electromechanical lock mechanism for interlocking a bolt elementand keeper element of a closure, said mechanism comprising:

a movable one of said interlocking elements, including resilient meansfor biasing said movable element in a direction to interlock with theother of said elements; means for guiding the extending and retractingmovements of said movable interlocking element into and out ofinterlocking relation with said other element;

an electric motor device, including means for controlling the supply ofelectric power to said device;

and means for coupling said motor device to said movable -interlockingelement for initiating said out-oflocking movements, said coupling meansincluding resilient means for storing energy supplied by said motordevice and in an amount sufficient to effectuate said out-of-lockingmovement and for transmitting said energy to said movable element in adirection to effectuate said out-of-locking movement, and means betweensaid motor device and said resilient coupling means for maintaining saidresilient coupling means in an energy-storing condition when said motordevice is de-energized and after having been placed in an energy-storingcondition by said motor device, so that upon operation of said motordevice for said out-of-locking movement said resilient means receivesand retains the energy therefor when said movable interlocking elementis restrained from out-of-locking movement;

said power controlling means including switch means for energizing saidelectric motor device to supply sufficient energy to said resilientmeans to move said movable element out of said interlocking relation andfor thereafter terminating the energization of said device.

2. An electromechanical lock mechanism as set forth in claim 1 whereinsaid switch means includes means for energizing said motor device toinitiate movement of said movable element into said interlockingrelation and thereafter terminating the energization of said device.

3. An electromechanical lock mechanism as set forth in claim 2 whereinsaid coupling means includes additional resilient means energized at thetime of initiation of the movement of said movable element into saidinterlocking relation and adapted for storing energy and for thereaftersupplying said stored energy to said movable element to assist in saidout-of-locking movement of said movable element.

4. An electromechanical lock mechanism as recited in claim 1 whereinsaid means for controlling the supply of power to said mot-or deviceincludes a timing device having first electrical switch means and meansfor operating said switch means during certain time periods, andadditional manually operable switch means effective to initiate thesupply of power to said motor device for out-of-locking movement of saidmovable element only during time periods of operation of said'firstswitch means.

5. An electromechanical lock mechanism as recited in claim 4 whereinsaid manually operated switch means includes a switch, and a mechanicalkey-operated device for said switch.

6. An electromechanical lock mechanism as recited in claim 1, andfurther comprising a mechanical key-operated device including means formoving said movable element out of locking relation; said coupling meansincluding means for accommodating said out-of-locking movement initiatedby said key-operated device without interference from said resilientmeans and for transmitting the stored energy from said resilient meansto said movable element to effectuate an out-of-locking movementthereof.

7. An electromechanical lock mechanism as set forth in claim 1 whereinsaid means for maintaining the energy storing condition of saidresilient coupling means includes a mechanism having a mechanicaladvantage connected from said motor device to said resilient meanswhereby said de-energized motor device is substantially unaffected byforces from said resilient means.

8. An electromechanical lock mechanism as set forth in claim 1 whereinsaid resilient means includes spring means having a displacementcorresponding to the displacement of said movable element frominterlocking to out-of-locking relation, said motor device being coupledto said spring mean-s to produce said displacement thereof whensupplying said energy for storage thereby, said spring means beingcoupled to said movable element to produce said displacement thereofwhen supplying said stored energy thereto.

9. An electromechanical lock mechanism for interlocking a bolt elementand keeper element of a closure, said mechanism comprising:

a movable one of said interlocking elements;

means for guiding the extending and retracting movements of said movableelement into and out of interlocking relation with said other element;

an electric motor device coupled to said movable element;

and means for controlling the supply of electric power to said device toeffectuate interlocking and out-oflocking movements of said movableelement; said controlling means including a control device having firstelectrical switch means and means for operating said first switch meansin one way at certain times to initiate the supply of power to saidmotor device for interlocking movement of said movable element and inanother way at certain other times, and additional manually operableswitch means for initiating the supply of power to said motor device forout-of-locking movement of said movable element only during time periodsof operation of said first switch means in said other way.

10. An electromechanical lock mechanism as recited in claim 9 whereinsaid manually operated switch means includes a switch, and akey-operated device for said switch; and further comprising a mechanicalkey-operated device for moving said movable element out of lockingrelation during time periods of operation of said first switch means insaid one way.

References Cited UNITED STATES PATENTS 2,070,803 2/1937 Oblak 292-1442,716,567 8/ 1955 Turcott 292-144 2,763,797 9/1956 Dean 318-475 X2,789,426 4/1957 Hollins -272 X 3,234,766 2/1966 OBrien 70-271 3,242,7083/ 1966 Sanchez 70-277 BOBBY R. GAY, Primary Examiner.

1. AN ELECTROMECHANICAL LOCK MECHANISM FOR INTERLOCKING A BOLT ELEMENTAND KEEPER ELEMENT OF A CLOSURE, SAID MECHANISM COMPRISING: A MOVABLEONE OF SAID INTERLOCKING ELEMENTS, INCLUDING RESILIENT MEANS FOR BIASINGSAID MOVABLE ELEMENT IN A DIRECTION TO INTERLOCK WITH THE OTHER OF SAIDELEMENTS; MEANS FOR GUIDING THE EXTENDING AND RETRACTING MOVEMENTS OFSAID MOVABLE INTERLOCKING ELEMENT INTO AND OUT OF INTERLOCKING RELATIONWITH SAID OTHER ELEMENT; AN ELECTRIC MOTOR DEVICE, INCLUDING MEANS FORCONTROLLING THE SUPPLY OF ELECTRIC POWER TO SAID DEVICE; AND MEANS FORCOUPLING SAID MOTOR DEVICE TO SAID MOVABLE INTERLOCKING ELEMENT FORINITIATING SAID OUT-OFLOCKING MOVEMENTS, SAID COUPLING MEANS INCLUDINGRESILIENT MEANS FOR STORING ENERGY SUPPLIED BY SAID MOTOR DEVICE AND INAN AMOUNT SUFFICIENT TO EFFECTUATE SAID OUT-OF-LOCKING MOVEMENT AND FORTRANSMITTING SAID ENERGY TO SAID MOVABLE ELEMENT IN A DIRECTION TOEFFECTUATE SAID OUT-OF-LOCKING MOVEMENT, AND MEANS BETWEEN SAID MOTORDEVICE AND SAID RESILIENT COUPLING MEANS FOR MAINTAINING SAID RESILIENTCOUPLING MEANS IN AN ENERGY-STORING CONDITION WHEN SAID MOTOR DEVICE ISDE-ENERGIZED AND AFTER HAVING BEEN PLACED IN AN ENERGY-STORING CONDITIONBY SAID MOTOR DEVICE, SO THAT UPON OPERATION OF SAID MOTOR DEVICE FORSAID OUT-OF-LOCKING MOVEMENT SAID RESILIENT MEANS RECEIVES AND RETAINSTHE ENERGY THEREFOR WHEN SAID MOVABLE INTERLOCK ELEMENT IS RESTRAINEDFROM OUT-OF-LOCKING MOVEMENT; SAID POWER CONTROLLING MEANS INCLUDINGSWITCH MEANS FOR ENERGIZING SAID ELECTRIC MOTOR DEVICE TO SUPPLYSUFFICIENT ENERGY TO SAID RESILINET MEANS TO MOVE SAID MOVABLE ELEMENTOUT OF SAID INTERLOCKING RELATION AND FOR THEREAFTER TERMINATING THEENERGIZATION OF SAID DEVICE.